<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <script src="1.js"></script>
</head>
<body>

</body>
<script>
  var b = 10;
(function b() {
  console.log(b)
  b = 5
  console.log(window.b)
  var b = 20
  console.log(b)
})()
</script>
</html>
